The invention pertains to a device for working and particularly grinding tooth profiles on a rotating toothed workpiece.
It is known to grind tooth profiles of a rotating toothed workpiece using at least two driven tools having toothlike protrusions. Such a tool may be a toothed wheel or a worm with its usual toothlike, raised spiral protrusions. The toothlike protrusions, hereinafter referred to simply as the tooth or teeth of the driven tools, have a width smaller than the desired width of the tooth gaps on the finished workpiece. In grinding tooth profiles using such known grinding processes, one driven tool at a time is rotated.
In U.S. Pat. No. 4,559,744 there is disclosed a grinding process using a globoidal worm-type grinding tool having molded teeth of a reduced width. This grinder can be readily adjusted to the desired axial distance relative to the workpiece axis, and thus is readily adjustable relative to the teeth to be ground. After the grinding tool is positioned relative to the teeth to be ground, the left and right tooth profiles are processed, one after the other, by making small angular displacements of the workpiece. As there is a complete, linear contact between the grinding worm profile and the tooth profile of the workpiece when grinding of the rough-work begins, an efficient grinding process is realized. However, there is a limit on the rim width which can be ground using this process.
An improvement in the aforementioned process is described in German Patent Document OS No. 34 01 340. This document describes a grinding process in which the grindable rim width can be enlarged by changing the axial position of the workpiece relative to the grinding worm between the grinding of the left profile and the grinding of the right profile. This process takes into account the fact that the possible contact line between the grinding worm profile and workpiece teeth is unsymmetrical relative to the distance between the workpiece axis and the grinding worm axis.
The two cited processes have the disadvantage that the left and right profiles have to be ground one after the other, which obviously results in an extended processing time. In addition, it is necessary to have a workpiece drive which operates very exactly, is torsion-proof and capable of exactly executing the small relative angular displacement for the rough-work and grinding adjustments.